The present invention relates to a ceramic and a method of manufacturing the same, a dielectric capacitor, a semiconductor device, and other elements including the ceramic of the present invention.
As a ferroelectric film applied to semiconductor devices (ferroelectric memory (FeRAM), for example), a ferroelectric film having a perovskite structure (PbZrTiO-type ferroelectric film, for example) and a ferroelectric film having a layered perovskite structure (BiLaTiO-type, BiTiO-type, or SrBiTaO-type ferroelectric film, for example) have been proposed. The ferroelectric film having a layered perovskite structure is generally formed by crystal growth from an amorphous state.
In the case of forming a ferroelectric film having a layered perovskite structure by using this formation method, the crystal growth rate in the c-axis direction becomes lower than those in the a-axis direction and the b-axis direction due to the crystal structure of the ferroelectric film. Specifically, crystals tend to be grown in the a-axis direction and the b-axis direction. Therefore, a ferroelectric film having a layered perovskite structure formed by using the above method has a rough surface morphology, whereby openings (holes or grooves, for example) are easily formed between crystals of the resulting ferroelectric film.
Generally, the above-described ferroelectric film must be sintered at a temperature as high as about 600 to 800° C. for a long period of time. Therefore, when forming a ferroelectric memory by combining a ferroelectric capacitor using such a ferroelectric film with a semiconductor element, it is necessary to prevent the semiconductor element from being affected by the high temperature treatment for a long period of time for forming the ferroelectric film. This gives rise to problems such as complexity of the manufacturing process for the ferroelectric memory.